The present invention relates to a process for continuously transferring, bonding and drying a film of a compound of an aqueous dispersion of a polymeric binder to a flexible substrate.
Surface laminated polymeric compounds are used in a wide range of applications. These compounds provide a tough shiny protective surface which may be impermeable. These coatings are useful as protective carrier coatings for foams and as protective backing coating for foam backed carpet. The coatings are also useful to provide a "skin" on non wovens which protect the non woven. These backed textiles are useful in a number of applications such as diapers, geotextiles and vapour barriers on insulation batts.
In the foam rubber industry there has been a desire to produce a rubber foam with the surface qualities of urethane foam. Preferably the foam should have a tough shiny surface. One approach to this problem is disclosed in U.S. Pat. No. 4,098,944 issued July 4, 1978 to Borg Warner Corp. This patent teaches spray coating the back of a carpet with from about 20 to 90 g/yd.sup.2 of a compound comprising 5 to 100 parts by weight of a latex of a carboxylated styrene butadiene rubber (X-SBR) and 100 parts of a hydrocarbon wax. The application of a "skin" to the back of a foam backed carpet has not been widely accepted in the carpet industry. It is difficult to get low coat weights for the surface finish and the surface tends to have an orange peel appearance rather than a smooth glossy appearance. The surface appearance of the foam has a strong influence on consumer selection of product.
Non wovens are a rapidly growing market in North America. In many cases it is desirable to apply a barrier coat to the surface of the non woven. This may be done by laminating or calendering a preformed sheet to the non woven web.
The Kirk Othmer Encyclopedia of Chemical Technology, John Wiley and Sons, New York, 1979, Vol. 6 at pages 377 through 411, discussed coated textiles and coating processes. Precast coating is known to be used with textiles and non wovens. In the process one or more coatings is applied to a flexible metal sheet which is contacted with the surface of the substrate to be coated. The present invention combines cast coating with drum lamination techniques to apply, bond, and dry a wet coating to a substrate in a simple efficient manner.